Most conventional automotive fuel systems use fuel injectors to deliver fuel to the engine cylinders for combustion. The fuel injectors are mounted on a fuel rail which is supplied with fuel by a fuel pump. The pressure at which the fuel is supplied to the fuel rail must be metered to ensure the proper operation of the fuel injector. Metering is carried out using a pressure regulator that controls the pressure of the fuel in the system at all engine rpm levels.
A conventional flow through pressure regulator is disclosed in U.S. Patent Publication No. 2006/0108007 A1 and includes a lower housing having a fuel inlet wherein a flow of fuel through the inlet communicates with a valve assembly through a fuel chamber defined by a fuel tube. In an open position of a valve element, the valve assembly regulates the flow of fuel through the lower housing to a fuel outlet. In a closed position, the valve element rests on a valve seat to prohibit the flow of fuel from the fuel chamber to the fuel outlet. A valve biasing member biases the valve element toward the fuel chamber in opposition to pressure extend on the valve element by the fuel in the fuel chamber. During normal operation, there is a potential for the valve biasing member to reach a resonant frequency and oscillate when turbulent flow occurs at the inlet, since fuel flow through flow areas of the regulator is balanced. Turbulent flow within the fuel system makes it difficult to determine if the valve element will have the appropriated biased movement in a single direction. The turbulent flow may result in unwanted noise being generated in the fuel system.
To reduce noise, conventionally, the cross section of the fuel tube of the regulator has been modified to create different inside diameters throughout the length of the tube. However, this approach has the disadvantage that many different parts are required for many specific applications, and it is difficult to ensure that the proper part is installed in the specific fuel regulator application.
Thus, there is a need to provide an improved flow through fuel pressure regulator that prevents or minimizes oscillation of the valve element when the regulator is exposed to turbulent fuel flow.